1. Field of the Invention
The present invention relates to a paper web reservoir apparatus used for the manufacture of cigarettes, for example.
2. Description of the Related Art
A cigarette manufacturing machine comprises a wrapping section for forming cigarette rod. The wrapping section is continuously supplied with a paper web, which travels in one direction on the wrapping section. As the paper web is moved, cut tobacco, which is fed onto the paper web at the starting end of the wrapping section, is gradually wrapped in the web. When the paper web passes the wrapping section, therefore, a continuous cigarette rod is delivered from this section. Thereafter, the cigarette rod is cut into pieces or individual cigarettes with a predetermined length.
In order to improve the efficiency of cigarette production or the operating efficiency of the cigarette manufacturing machine, the cut tobacco and the paper web must be continuously supplied to the wrapping section for a long period of time.
To attain this, the cigarette manufacturing machine is provided with a supply section for continuously supplying the paper web. The supply section includes a pair of web rolls, and the paper web paid out from one of these rolls is supplied to the wrapping section. Thus, in this case, the one web roll serves as a working roll, and the other as a spare roll.
When the remaining paper web of the working roll runs short, the leading end of a spare paper web paid out from the spare roll is connected to the working web from the working roll, and the working web is cut on the upstream side of the junction between the two webs. From this time on, therefore, the spare web is paid out as a new working web from the spare roll, and is supplied to the wrapping section.
The delivery of the paper web from the working roll should be stopped during this web roll changing operation. In order to allow the cigarette manufacturing machine to be operated without interruption during the web roll changing operation, however, the paper web supply to the wrapping section must be continued even during the changing operation.
Accordingly, the cigarette manufacturing machine comprises a paper web reservoir apparatus which is located between the wrapping section and the supply section. The reservoir apparatus is stored with the paper web which has a greater length than is needed to cover the time required for the change of the web roll. Thus even when the delivery of the paper web from the supply section is stopped during the web roll changing operation, the operation of the cigarette manufacturing machine can be continued by supplying the paper web from the reservoir apparatus to the wrapping section.
In storing the paper web in the reservoir apparatus, the speed of delivery of the paper web from the working roll should be increased to a level higher than the traveling speed of the paper web passing the wrapping section, that is, line speed.
In recent years, there is a tendency for the line speed of modern cigarette manufacturing machines to be increased for higher productivity. Accordingly, the speed of introduction of the paper web to be stored in the reservoir apparatus is very high. As the paper web is introduced into the reservoir apparatus, therefore, a heavy vortex air current is produced in the apparatus. This air current may twist or cut the paper web. Such twisting or cutting of the paper web hinders steady supply of the web from the reservoir apparatus to the wrapping section, thus constituting a great cause of interruption of the operation of the cigarette manufacturing machine.